The Carcinogen Bioassay Data System is used to collect, monitor, store, and report experimental data and results from bioassay operations. It is now in full operation with new bioassay experiments being entered as they are initiated. In the past year, over 208,000 data collection forms were processed and entered into the CBDS data base. During this period, special attention has been given to generating reports and analyzing data. For instance, the preliminary analysis report for a chemical was created: it includes a description of the experimental design, tumor and non-tumor incidence, summary tables by anatomic site and site of origin, individual animal pathology, table of tissues examined, and survival curve analysis. Statistical analysis of survival and specific tumor types was established using unadjusted and time-adjusted techniques. The unadjusted methods include the Armitage and Cox test for linear trend and Fisher-Irwin Exact test while the time-adjusted methods involved the Cox-Tarone test for trend. Many of the data tables, growth and survival curves and data analysis can be included in the Technical Reports now being developed. In addition, chemical and bioassay contract information subsystems are maintained.